One of the biggest question marks surrounding US national head coach Jurgen Klinsmann’s roster release on Thursday for two friendlies and a series of upcoming World Cup qualifiers was the second consecutive exclusion of longtime captain Carlos Bocanegra, and what to make of the former MLS star’s future with the US squad.

Bocanegra was left off the roster for qualifiers against Costa Rica and Mexico in March because of a lack of playing time with Spanish second-division club Racing Santander, and he won’t be back this time because of his club’s relegation battle and the fact that he’s fallen behind in the pecking order on the US backline.

Klinsmann called MLS stars Omar Gonzalez (LA Galaxy) and Matt Besler (Sporting Kansas City), as well as Stoke City’s Geoff Cameron and Brondby’s Clarence Goodson into camp as his center back options for upcoming friendlies against Belgium (May 29) and Germany (June 2) and three qualifiers next month.

“I have center backs coming out of extremely good performances against Costa Rica and Mexico,” Klinsmann told the media via conference call on Friday, “and those four guys we have are ahead of Carlos.”

It was no surprise then, that Klinsmann faced questions about excluding Bocanegra this time around while including right back Michael Parkhurst, who has played sparingly since joining German side Augsburg in December.

Although he acknowledged Parkhurst still hasn’t broken in with his club team, Klinsmann defended his decision to bring in the former New England Revolution star by citing the recent injuries to right back incumbents Steve Cherundolo (knee) and Timmy Chandler (knee).

“At the end of the day, it all comes down to the positions we have to fill,” Klinsmann said. “…[Parkhurst] is playing a position where Cherundolo and Chandler are both not available, and we’re in a situation where we have to make that compromise. We don’t have to make that compromise at center back – and I see Carlos only as a center back now, I don’t see him as a left back – and there, we are fully loaded.”

Klinsmann added that although Gonzalez started each of the team’s crucial qualifiers this spring, there are no guarantees he or Besler are the incumbent starters, or that Cameron will once again be deployed at right back.

“All four are on a very, very good level,” he said. “We’ll see what’s in camp and we’ll go from game to game.”